Mathematical Symbols

A symbol, in the form of a line, can be used to show the parts of a shape that have congruent sides. The lines on the sides of this trapezoid below show that the two non-parallel sides are congruent.

If there is more than one pair of congruent sides on a figure, then sometimes two, three, or even four lines must be used to show congruency. The dashes on this rectangle are showing you that the pairs of opposite sides are congruent to each other.

The symbol that represents a right angle is in the shape of a box. For instance, the symbols in the corners of this rectangle are showing you that it has 4 right angles.

Congruent angles, not 90°, are shown using curved lines. The curved lines in the corners of this trapezoid are showing that those angles are congruent.